Four fire engines and around 25 firefighters were called to a fire at a flat above a shop on High Road in Tottenham.
Most of a flat on the first floor of the two-storey building was damaged by the fire. Two people left the building before the Brigade arrived. They were treated at the scene by London Ambulance Service crews.
The Brigade's fire investigators believe the fire was accidental and caused by the failure of lithium-ion batteries for an electric bike.
A London Fire Brigade spokesperson said: "The occupier was alerted to the fire when there was a pop and smoke poured out of an electric bike battery pack that was being charged.
"Batteries can present a fire risk if they're over-charged, short circuited, submerged in water or damaged, so it's really important to protect them against being damaged and charge them safely.
"Unplug devices once they have finished charging and make sure you use the right charger for your device."
The Brigade was called at 1853 and the fire was under control by 1956. Fire crews from Tottenham, Stoke Newington, Holloway and Hornsey fire stations were at the scene.